Elastic band, in particular upholstery band

ABSTRACT

The invention pertains to an elastic band, in particular for upholstery on the backrests of chairs, etc. The band has rubber threads (2, 2a, 2b) running in its longitudinal direction. On both sides of the rubber threads, running transverse to them, are from and back woof threads (4, 6) made of inelastic textile material. The band is designed for crochet production. It has weave threads made of inelastic material, with each rubber thread (2, 2a, 2b) having two weave threads (7, 8) one of which, as stationary weave thread (7), always loops around the same rubber thread as well as the front and back woof threads (4, 6). The other, the jump weave thread (8) makes loops around a first rubber thread (2a) and around a small, odd number of successive from and back woof threads (4, 6). It then jumps to a neighboring second rubber thread (2) and with it makes an equal number of successive front and back woof-thread loops. It then jumps back to the first rubber thread (2a), etc.

The invention pertains to an elastic band, produced by crocheting havingthe features recited in the preamble of claim 1. The invention isapplicable particularly to an upholstery band, as is required for thebackrests of chairs, armchairs or couches. Elastic bands, made bycrocheting, having the features recited in the preamble of claim 1 areknown from the documents U.S. Pat. No. 4,248,064 and GB-A-967 570. Thereis provided one stationary weave thread for each rubber thread, whichloops around the same rubber thread as well as the front and back weftthread. For upholstery, the bands are attached to wooden frames bytacks. In most cases also these threads will be cut off. The band thenunravels from these points during use.

The upholstery bands cross one another within the upholstery frame.During use they stretch and slip relative to one another, producing adisturbing sound if they are conventional, relatively rough bands.

The present invention is to provide an elastic band meeting thefollowing conditions at one and the same time:

1. Starting from not covered rubber threads, the band is to beproducible on a single machine, namely a crocheting machine.

2. The band is to be protected against unravelling, even at damagedlocations.

3. The band is to have a smoother surface than conventional ones andtherefore not produce any sound during use.

4. The band, while having the same load-carrying capacity as aconventional elastic band, is to be thinner than the latter.

These advantages are attained by a crocheted elastic band according toclaim 1.

An exemplary embodiment incorporating further features of the inventionwill be described below with reference to the drawings.

FIG. 1 is a portion of a crocheted elastic band according to theinvention, depicted in highly schematized form.

FIG. 1a is a schematized cross section of the band in FIG. 1, parallelto the weft threads.

FIG. 2 is a side view of the head end of a conventional bearded needle.

FIG. 3 is a side view of the head end of a bearded needle suited forproducing a crocheted elastic band according to the invention.

FIG. 1 depicts in highly schematized form a small portion of a crochetedelastic band according to the invention. The band has rubber threads 2,2a, 2b, by which threads made of rubber or artificial rubber, generallythreads of high elasticity, are meant. The band has weft threads runningtransversely to them, namely front weft threads 4 and back weft threads6.The designations "front" and "back" correspond to the representationin FIG. 1. These weft threads are made of relatively inelastic textilematerial. No loops or other form of covering is provided around therubberthreads 2, 2a, 2b, saving a respective operation.

FIG. 1 further shows that each of the rubber threads 2, 2a, 2b togetherwith the front and back weft threads 4, 6 has loops of one of the weavethreads 7 around it. Since these weave threads 7 make loops along onlyonesingle rubber thread, they are therefore referred to here as"stationary" weave threads.

Also shown are weave threads 8, 8a, 8c crossing from one rubber threadto another and therefore referred to here as "jumping" weave threads.These jumping weave threads loop around the rubber threads 2, 2a, 2b onthe one hand, around the back weft threads 6 on the other hand, but notaround thefront weft threads 4. Along the rubber thread 2a the jumpingweave thread 8(at the top in FIG. 1) loops around three successive backweft threads 6 and the rubber thread 2a. It then jumps leftwards to theneighbouring rubber thread 2, loops around it at three successivecrossing points of the rubber thread 2 and only the back weft thread 6.The jumping weave thread 8 then jumps back to the original rubber thread2a, loops around itat three further crossing points in theabove-described manner and jumps back again to the same neighbouringrubber thread 2 and so on.

A jumping weave thread 8a at the right side of the weave thread 8 isguidedin the same way. At the left in FIG. 1 a further jumping weavethread 8c isto be seen, crossing over from a rubber thread (notillustrated) on the left. The same applies for the righthand side ofFIG. 1. These jumping weave threads are used throughout the width of theband.

Instead of looping around three successive crossing points asillustrated in FIG. 1, the jumping weave threads may loop around anotherodd number ofsuccessive crossing points, e.g. three to nine.

Since the weave threads (8, 8a, 8b,) are guided beneath the from weftthreads 4, the latter protect the weave threads from wear in thefinished woven band.

The stationary weave threads 7 loop around the two weft threads 4,6 andalso around the jumping weave threads 8, 8a, 8c and protect particularlythe jumping weave threads at the front and back from chafing.

It follows from the illustrated loop system that the finished banddisplaysless roughness.

FIG. 2 shows the head end of a normal patent needle for crochetingmachines. FIG. 3 shows the head end of a patent needle 10 suited forproducing an elastic band according to the invention. The height h ofthe beard 12 is here made larger than in normal patent needles bybuckling. This is appropriate because the jumping weave threads jumpover two needles. By this means they are conducted to the patent needlesat angles,which would impede or prevent insertion in normal needleheads.

I claim:
 1. An elastic band produced by crocheting, in particular anupholstery band, the elastic band having a longitudinal direction andcomprising:rubber threads running in the longitudinal direction; frontand back weft threads made of relatively inelastic textile material,said front weft threads located on one side of the rubber threads andrunning transversely thereto, and said back weft threads located on theopposing side of the rubber threads and running transversely thereto;weave threads made of relatively inelastic textile material; wherein foreach rubber thread, a first weave thread is provided which always loopsaround the same rubber thread and the front and back weft threadsassociated with the same rubber thread; wherein for each rubber thread asecond weave thread is provided which loops around only its respectiverubber thread and the weft thread on one side of the rubber thread; andwherein each second weave thread repeatedly: loops around a first rubberthread and a small, odd number of successive weft threads on said oneside of the rubber threads, then jumps to a second and neighboringrubber thread and loops with it and an equal number of small, odd numberof successive weft threads on said one side of the rubber threads, andthen jumps back to the first rubber thread.
 2. An elastic band asclaimed in claim 1, wherein no covering is provided around the rubberthreads.
 3. An elastic band as claimed in claim 1, wherein the weftthreads on said one side of the rubber threads are the back weftthreads.
 4. An elastic band as claimed in claim 3, wherein the small,odd number of loops made around the back weft threads between jumps isbetween three and nine.
 5. An elastic band as claimed in claim 4,wherein the small, odd number of loops made around the back weft threadsbetween jumps is three.